This invention relates to a tube filling apparatus. In particular, but not exclusively, the invention relates to an apparatus for filling paper tubes with processed plant material, such as a herb mixture, for example.
Paper, cellulose or hemp tubes are often filled by processed plant material, such as a herb mixture, to allow it to be set alight so that it can be smoked. Traditionally, paper tubes have been filled manually by inserting an amount of herb mixture into the tube and thereafter compacting the mixture by striking it on a hard surface until a desired density is obtained. This manual process of filling tubes typically takes about two to three minutes, depending on the quantity, quality and density of the fill required.
A number of different devices have been suggested to address the shortcomings of the manual filling process. In one of these known devices a compacted cartridge of the herb mixture is inserted into the paper tube using a sliding mechanism. The problem with this device is that only one paper tube can be filled at a time. In another device, which allows multiple paper tubes to be filled, a number of vertically arranged tube receiving cavities is provided in a body made from polystyrene. The empty paper tubes are placed in the recesses and then filled manually with the herb mixture. The herb mixture inside the paper tubes is then compacted by lifting the body and dropping it onto a hard surface. This is repeated until the desired fill density has been reached. Although this device allows the herb mixture in the various tubes to be compacted simultaneously, one of its disadvantages is that it still requires a user to impact the polystyrene assembly on a hard surface manually.
Yet another known device includes a number of paper tube holders which are, in use, carried pivotally at the ends of arm extending from a vertically arranged shaft. The paper tubes are placed in cavities in the holders and filled with the herb mixture. After the tubes have been filled the vertical shaft is spun in order to use centrifugal force to compact the herb mixture in the tubes. One major disadvantage of this device is that it includes many movable components which require maintenance in order to keep it in working condition. The device is also bulky as its rotating arms take up a fair amount of space. Yet another disadvantage of this known device is that the filled tubes often require further compacting to achieve an acceptable density.
Another, more compact, device includes a holder which again has a number of tube receiving cavities which are, in use, arranged vertically. The holder is supported on a base to which an electrical motor is attached. A counterweight is attached to the shaft of the electrical motor to cause the base to vibrate in order to compact the herb mixture in the paper tubes inside the cavities in the holder. The holder is carried on top of the vibrating assembly and, in addition to drifting around on the assembly, it is also required that both the base and holder be vibrated during the compacting process. It has been found that the base's displacement is minimal and, accordingly, the effect on the tubes and herb mixture is also minimal. As a result a very loose fill is achieved, which is far from desirable. The herb mixture density achieved by using this device is roughly about half of that achieved by manually compacting the mixture by striking it on a hard surface. It is believed that this is due to a rotational movement being imparted onto the tubes as opposed to a desired bouncing, impacting movement.
Yet another known device includes a filling assembly which is, in use, supported by a housing forming the base of the device. A number of paper tubes are placed in the filling assembly and filled with the herb mixture. Inside the base an electrical motor is mounted to drive a cam mounted on a shaft. A mechanical coupling in the form of a belt drive is used to transfer rotation of the motor shaft to the cam carrying shaft. The filling assembly is mounted above the cam so that rotation of the cam carrying shaft results in the cam striking the bottom of the filling assembly to administer a series of jolts or raps on the filling assembly. To ensure that the herb mixture inside the tubes is compacted, the tubes and cavities in which they are housed allow for a tight fit so that the tube and filling assembly moves in harmony during the compacting process. One problem with this known device is that it again includes many movable components. However, a more serious disadvantage is that it requires the entire filling assembly to be vibrated to compact the herb mixture. The combined weight of the tubes, herb mixture and filling assembly places limitations on the magnitude of displacement that can be realistically and safely applied. It is also not ideal simply to increase the size of the electrical motor and mechanical components causing the vibrating action to improve the achieved mixture density as this would result in the increase in overall costs, size and weight of the device. The increase in the size of the electrical motor and mechanical components would also impact the rise time and dead stroke time of the filling assembly.
It has been found that the known methods and devices as described above either do not allow for the simultaneous filling of multiple paper tubes or for the compacting of the herb mixture to a satisfactory degree. When using the known devices it is generally required that the herb mixture be compacted further manually after having removed the paper tubes from the devices in order to get a satisfactory herb mixture density.
It is an object of this invention to alleviate at least some of the problems experienced with known methods and devices.
It is a further object of this invention to provide a tube filling apparatus that will be a useful alternative to existing devices.